ST STCS1A 恒流高亮LED参考设计方案

ST公司的STCS1A 是一款可变输入电压源提供精确BiCMOS工艺恒流源。主要用于5V、12V和24V LED驱动器替代分立元件解决方案，具有高精确性、高集成性和高可靠性特点。恒流可通过一个外部电阻进行调节，最大输出电流为1.5A（正负10%精度），可通过专用引脚执行PWM进行调光控制。可通过外部电容电流上升斜率，以减少EMI影响。本文首先介绍芯片的简介、特性、内部框图及应用领域，并给出相应设计方案的设计原理图、元器件列表及PCB元件布局图。

The STCS1A is a BiCMOS constant current source designed to provide a precise constant current starting from a varying input voltage source. The main target is to replace discrete components solution for driving LEDs in low voltage applications such as 5 V, 12 V or 24 V giving benefits in terms of precision, integration and reliability.

The current is set with external resistor up to 1.5 A with a ± 10 % precision; a dedicated pin allows implementing PWM dimming. An external capacitor allows setting the slope for the current rise from tens of microseconds to tens of milliseconds allowing reduction of EMI.

An open-drain pin output provides information on load disconnection condition.

STCS1A主要特性：

■ Up to 40 V input voltage
■ Less than 0.5 V voltage overhead
■ Up to 1.5 A output current
■ PWM dimming pin
■ Shutdown pin
■ LED disconnection diagnostic
■ Slope control with external cap
..

查看全文